9: Transport in animals Flashcards
What is circulatory system?
a system of blood vessels with a pump and valves to ensure one-way flow of blood
Describe the single circulation of a fish
Fish
- two heart chambers
- per circuit blood goes through heart once
heart ➝ gills ➝ body = repeat
Describe the double circulation of a mammal
Explain its advantages
Mammals
- four heart chambers
- per circuit blood goes through heart TWICE
heart ➝ lungs ➝ heart ➝ body
Why?
Mammals have greater need for oxygen to use in respiration for warmth
- can maintain high blood pressure = increase the speed in nutrient delivery + waste removed = more efficient
Describe the blood flow
Right side of heart (technically left)
- deoxygenated blood enters vena cava, right atrium, AV/ tricuspid valve, right ventricle, semilunar valve, pulmonary artery, lungs
Left (technically right)
- pulmonary vein, left atrium, AV/ bicuspid valve, left ventricle, semilunar valve, aorta (artery) = body, vena cava
What is a septum? Why is it important?
Separates 2 sides of the heart,
prevents the mixing of deoxygenated and oxygenated blood
Describe relative thickness of the muscle wall of left and right ventricle
Right - lungs
Left ventricle - pumps blood around the body - further distance = blood under higher PRESSURE
Describe relative thickness of the muscle wall of atria compared to ventricles
Ventricles pump blood around the body/ lungs = need to withstand higher pressure
Atria - only to ventricles = lower pressure
What tissue is the heart made of?
cardiac muscle
What is the function of coronary artery?
supplies heart muscle with blood
Describe coronary heart disease: why does it happen?
blockage of coronary arteries
by buildup of cholesterol ➝ limiting blood flow to heart
How to measure heart’s activity?
Electrocardiogram - ECG
pulse rate
valve activity - listening to sounds of valves closing
What are risk factors of coronary heart disease (6)
how to prevent
smoking, diet, stress, genetic predisposition, age, gender
exercise regularly control diet - less saturated fats, fruit, veg
no smoking, drinking
Treatment of coronary heart disease
Drug treatment - ASPIRIN (thins blood, platelets less likely to clump)
Surgery - stent, angioplasty, bypass
Effect of physical exercise on the heart rate [4]
heart rate increases
short term: muscles respire to produce energy
aerobic respiration requires oxygen = heart rate increases = blood pumped quicker = more oxygen is delivered to respiring tissues
- adrenaline stimulates increase in heart/pulse rate
- increase of carbon dioxide concentration in blood
- nerves stimulate heart to beat faster
- muscles require more energy, so rate of aerobic respiration increases
- increase demand for oxygen/glucose; quicker removal of CO2 /lactic acid
- more blood to lungs per unit time is needed
- more blood/oxygen/glucose to muscles
(pulse rate is exactly equal to the heart rate, as the contractions of the heart cause the increases in blood pressure in the arteries that lead to a noticeable pulse)
Valves
prevent back flow of blood